1. Field of the Invention
The present invention relates to device-to-device communications. More particularly, the present invention relates to a method and an apparatus for assigning connection identifiers for use in the device-to-device communications.
2. Description of the Related Art
Following a development of a communication apparatus and a communication system, users of the communication apparatus are in need of services for easily obtaining or sharing desired information. Recently, an introduction of smart phones and tablet Personal Computers (PCs) has provided circumstances for obtaining and sharing a wide variety of information through a wireless communication. However, the wireless communication system has a problem in that the users may obtain or share desired information only when a communication infrastructure is constructed. In addition, it may not be easy for the wireless communication system to effectively provide minor but useful real-time information in a daily living space due to the complexity of the system or time delay.
Accordingly, a Device-to-Device (D2D) service in which a communication can be directly performed between devices is emerging. In the D2D service, communication is not performed between devices through network objects such as base stations. Rather, in the D2D service, communication is performed through a device-to-device communication link in a space without a communication infrastructure.
The devices that support the device-to-device service can discover a neighboring user equipment by preset resources during a preset time period and generate Connection IDentifiers (CID) for communication connections with a peer user equipment to perform communication. That is, if there is a plurality of user equipments that can attempt a device-to-device communication within a short range, a plurality of connections may exist among a plurality of devices, and the plurality of connections may simultaneously attempt data transmission. Each of the connections is identified by a unique CID, and the corresponding connection is approved if the corresponding CID is selected.
Each connection may transfer a large quantity of data or a small quantity of data depending on types of data transmission. That is, a user equipment can sporadically or periodically transmit or receive data even when a CID is assigned. In this case, a connection to which the CID is assigned occupies its own resources when the connection is not in use, and therefore there is a problem in that a waste of the resources assigned to the connection may result.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.